1. Field of the Invention
This invention relates to the field of computer system power supplies and, more particularly, to a system and method for providing hot-swap status indication in a computer system having redundant power supplies.
2. Description of the Related Art
To maximize return on investment in computer systems and provide reliable service to system users, computers must be designed with the goal of minimum system downtime and maximum system availability. Because the failure of key components can lead to a loss of system availability, many key components, such as power supplies, are designed to provide redundant capacity and thus still provide for normal operation of the system even in the event of a component failure.
For example, a redundant power supply may include two separate power supplies, each capable of powering the system individually. Under normal operation, both power supplies are operable to share the power load, with each power supply operable to provide half the required power. However, in the event of failure or removal of one of the power supplies, the other power supply is operable to provide full power to the system.
To further minimize system downtime, key components in the computer system may be designed to be hot-swappable. Hot-swapping is a method for removing or replacing a component of a computer system without shutting down or restarting the system, thereby providing system availability even as the system is being serviced or repaired. In a system that provides hot-swappable redundant power supplies, one of the power supplies may be removed and serviced while the remaining power supply continues to power the system.
In some systems that provide redundant power supplies, the output voltage of each supply may be monitored to provide an indication that each power supply is providing sufficient voltage, and thus that one of the power supplies may be hot-swapped. However, in some instances even a power supply which provides a voltage within the desired specification may not be providing sufficient power to allow for the removal of the other power supply.
Furthermore, it may be at times desirable to add additional components to the computer system to provide new capabilities or enhanced functionality. However, the addition of these components may increase the system power load such that neither individual power supply has sufficient capacity to fully power the system. In such situations, a user may detrimentally attempt to hot-swap a power supply.